Push-in type lamp holder



y 1958 H. BAUER ETAL PUSH-IN TYPE LAMP HOLDER 3 Sheets-Sheet 1 FiledSept. 30, 1954 May 20, 1958 H. BAUER ET AL 2,835,878

PUSH-IN TYPE LAMP HOLDER Filed Sept. 30, 1954 3 Sheets-Sheet 2 .May 20,1958 H. BAUER ET AL 2,835,878

PUSH-IN TYPE LAMP HOLDER Filed Sept. 50, 1954 s Sheets-Sheet vs FIG. 8-

United States Patent :Office 2,835,878 Patented May 20, 195 8 PUSH-INTYPE LAMP HOLDER Heinz Bauer, Essen, and Heinrich Eul and HelmutGiinther, Emmerich, Germany Application September 30, 1954, Serial No.459,404

Claims priority, application Germany October 5, 1953 3 Claims. (Cl.339-42) The invention relates to a push type lamp socket with resilientprojections engaging with peripheral abutments of the lamp base,particularly with threads of the lamp base, the projections servingtokcep the lamp in its pushed-in position.

In one of the well-known arrangements of this type, the resilientprojections consist of peripheral ribs cooperating with correspondingperipheral grooves of the lamp base. The casing is slit axially and,when the lamp is pushed in, is extended in such a manner as to allow theperipheral ribs to snap into the grooves of the lamp base, spring ringsbeing provided to assist the spring action of the casing.

The reliability of such sockets leaves much to be desired, apart fromthe fact that their manufacturing costs are relatively high.

According to our invention, the projections consist of blades pivotallyarranged at the circumference of the push type lamp socket and drawn,when no lamp is pushed-in into a radial plane by an annular springengaging projections which are provided on each of the blades. On pushin-in a lamp they are rocked by the insertion of the lamp base about theirpivots whereby their free ends snap over the peripheral abutments of thelamp base.

The advantages of this arrangement are its application to the lower partof any ordinary lamp socket, its lower manufacturing costs, and the factthat it gives the lamp a reliably firm hold. In addition the seat of thelamp is resilient and movable so that welding or corrosion of thepositioning elements and socket contacts is prevented when sparks form,or such effects may easily be neutralized by moving the lamps to andfro. Due to the resilient seating, this holder is advantageousparticularly also in such cases where the lamp is exposed to heavyvibration such as on vehicles, in engine rooms and the like.

Located at the upper part of the inlet opening the blades cover up themajor part of it thus serving as a shield against electric shock hazard,i. e. the fingers of the hand are prevented from inadvertently enteringthe inlet opening and from touching the contacts.

The annular spring is preferably in the form of a helical spring shapedinto a ring, which engages deflected tongues punched out from the centreof the blades.

Other features of the invention are apparent from the followingdescription of some embodiments of the invention.

In the accompanying drawing:

Fig. 1 is a vertical cross section of the upper part of a lamp socketaccording to our invention.

Fig. 2 is a plane view of the lamp socket shown in Fig. 1.

Fig. 3 is a plan view of a single blade of a socket according to Figs. 1and 2 at an enlarged scale.

Fig. 4 is a side elevation of the blade according to Fig. 3.

Figs. 3a and 4a are plan and side views, respectively, corresponding toFigs. 3 and 4 of a modification of the invention.

Fig. 5 is a vertical cross section of a modified form of blade mounting.

Fig. 6 is a plan view partly broken away of the device according to Fig.5.

Fig. 7 is a plan view of a further form of blade mountmg.

Fig. 8 is a side elevation partly in section of the lamp socket with alamp.

By means of a thread 3 (Figs. 1 and 8) the base 24 (Fig. 8) of thesocket is screwed on to an upper part or shell 2 in a well-known manner.The shell has an inlet opening 4 which widens into an extension 5 at itsupper part. This extension has a recessed surface 6, on which issupported a ring 7 having at its peripheral edge a number of recesses 8(Fig. 3). At each side of the root of each recess is is formed a smallrecessed portion 9, the small recessed portions serving as bearings forthe lateral projections 11 of the blades 12 which are supported on thering 7. The blades 12 are provided with downwardly directed tongues 13punched out of the blades.

' An annular helical spring 14 is provided behind the deflected tongues13. In their inoperative position, the blades are supported by the ring7 in a manner shown in Figs. 3 and 4. The blades 12 are inserted withtheir narrow ends into the clearances 8 till their lateral projections11 have reached the recessed portions: 9. Thereupon their free ends arebrought into a horizontal position so that they extend underneath thering in a radial plane and the annular spring 14 is placed behind thetongues.

It will be understood from the drawing that, when the lamp base 10 isintroduced into the inlet opening, as shown in Fig. 8 and, by dash anddot lines, in Fig. 1, the blades 12 are swwung downwards and outwardsagainst the increasing tension of the annular spring 14' and; at thesame time and with considerable spring pressure, their free ends engagewith the threads of the lamp base (see the position of the left blade inFig. 1 marked by dash and dot lines). At least one of the blades will bein intimate contact with a Wall part of the thread, so that the lampcannot be withdrawn without application of an increased power oftraction or without being unscrewed.

When the blades are of different lengths, it will be possible to makeall blades simultaneously contact the wall parts of the threads of thelamp base or cause them eventually to take up this position after aslight rotation. In their position of rest (see Figs. 1 and 2) the endpoints of the blades trace out a spiral. Corresponding different lengthsmay be given to the blades by a simple punching action, when the pushtype lamp socket is finished.

The ring 7 is covered by a covering ring 15 made of a plastic or othersuitable material, which covering ring is provided with an annulargroove above the recessed portions 9, so as not to hinder the pivotingof the blades 12. The covering tin- 15 is secured in position by aspring ring 16.

Longitudinal ribs 17 are provided in the lower, narrower part of theinlet opening 4 to centralize the lamp base, when it is pushed in. Theblades enter the clearances between the longitudinal ribs 17, when theyare swung downwards by a lamp base. In order to ensure that the bladesare not prevented from swinging downwards by the ribs 17, the ring 7 issecured by means of a groove-and-tongue joint 18 to maintain it in apredetermined position inside the shell 2.

Referring to Figs. 3a and 4a, the blades 12, at their outer ends, areprovided with a narrow transverse slot 19 adapted to be slid over afinger 20 bent downwards from the ring 7. The blades 12 can also bemounted by bond ing over their outer ends and embracing a wire ring orby means of transversal pins fixed at their outer ends.

Referring to Figs. 5 and 6 the mounting of the radial blades 12 iseffected by means of a bearing ring 21 made of plastic and, at its lowerpart, is provided with projections 22 equi-spaced according to the widthof a blade 12.

At their roots, the projections 22 are provided with recesses 23 inwhich engage the projections 11 of the blades. The bearing ring does notrequire a cover ring because it is secured to the ,shell 2 of the socketby means of a spring ring 16.

In the modification according to Fig. 7 the blades 12 of difierentlengths together with their ring 7 consist of one single piece punchedout of a thin and resilient sheet of material. The articulated joint ofthe blades is replaced, in this instance, by the flexibility of theblades, which allows bending down of the blades 12, when the lamp baseis introduced into the holder. The annular spring 14 is also used andisengaged behind the downwardly bent tongues 13 to ensure the pressurerequired for the pressing of the blades against the lamp base and forthe withdrawal of the blades into their position of rest, when the lampbase is withdrawn.

The lamp base may also be provided with a cylindrical circumferentialface instead ofwith an Edison-screw thread, the face havingcorresponding peripheral grooves or other recesses or elevations.

The design according to the invention does not require any enlargementof the largest diameter of the usual socket body 2. As the lamp is notscrewed in but simply pushed in, it is not necessary to provide the lampsocket with elements to guard it against being screwed in relation tothe supporting members, which elements are generally in the form ofscrews with clamping rings and the provision of which considerablyincreases the manufacturing costs of the sockets. The invention allowsthe lamp to be disconnected by a slight rotation, as the thread of thelamp engages the points of the blades.

What we claim, is:

1. In a push type lamp socket of the class described, a socket bodyhaving an inlet opening, current carrying parts located therein, a lampbase to be inserted therein having peripheral abutments, at least fourblades terminating in free ends and connecting ends, the latter beingmounted on the inside of the socket body, connecting means between saidsocket body and said connecting ends adapted to enable the free ends tobe swung in an are, a projection at the under side of each blade betweenits free end and its connecting end, an annular spring simultaneouslyengaging all said projections adapted to draw the blades towards theaxis of the socket body into a radial plane of the socket body, when nolamp is inserted, and to return the free ends of the blades behind saidabutments, after said blades have been swung outwards by an angle ofabout degrees on inserting the lamp, whereby said blades serve as aprotection against touching said current carrying parts and hold thelamp in its inserted position in such a manner that it cannot be drawnout of the socket body without an increased power of traction.

2. In a push-type lamp socket according to claim 1, said connectingmeans having the form of pivots consisting of lateral projections at theouter ends of the blades, a ring having spaced recesses therein whichextend inwards from its outer periphery and recessed portions located atthe internal ends of and lateral to said recesses, said lateralprojections being positioned in said recessed portions, and means forholding said lateral projections in said recessed portions.

3. In a push type lamp socket according to claim 1, said connectingmeans having the form of pivots consisting of lateral projections of theouter ends of the blades, and a bearing ring having downwardly directedprojections equi-spaced according to the distance of the blades fromeach other, said projections having outer recesses below the undersideof the bearing ring, the lateral,

projections of said blades extending into said recesses.

References Cited in the file of this patent V UNITED STATES PATENTS1,663,264 Thompson n. Mar. 20, 1928 1,761,335 Graves June 3, 19302,031,296 Alsaker et a1. Feb. 18, 1936 2,468,846 Trainor May 3, 19432,636,068 Perkins Apr. 21, 1950

